Re: [PATCH] usb: gadget: composite: enable BESL support

[Felipe Balbi]

On Tue, Apr 28, 2015 at 07:56:13AM +0000, Du, Changbin wrote:
> From a6615937bcd9234e6d6bb817c3701fce44d0a84d Mon Sep 17 00:00:00 2001
> From: Felipe Balbi <balbi@xxxxxx>
> Date: Tue, 30 Sep 2014 16:08:03 -0500
> Subject: [PATCH] usb: gadget: composite: enable BESL support

missing upstream commit.

> According to USB 2.0 ECN Errata for Link Power
> Management (USB2-LPM-Errata-final.pdf), BESL
> must be enabled if LPM is enabled.
> 
> This helps with USB30CV TD 9.21 LPM L1
> Suspend Resume Test.
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # 3.14

this should be backported all the way back to 3.1. The commit which this
patch is fixing, was applied on v3.1, so we're probably going to
backport to 3.10 and 3.14. When asking for backports, don't consider
only your project, think about the kernel/stable releases as a whole.

BTW, that should be v3.1+, the + tells the Stable team that from v3.1
forward, all kernels need the backport.

> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
> ---
> Hi,
> 
> This patch was introduced on v3.18. However the issue fixed already existed on
> v3.14 and v3.14 is a long term support version.

the issue already existed on v3.1, why did you decide to backport only
to v3.14 ?

> So propose to backport it over there as well.
> 
> Du, Changbin
> ---
>  drivers/usb/gadget/composite.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index a8c18df..f6a51fd 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -560,7 +560,7 @@ static int bos_desc(struct usb_composite_dev *cdev)
>  	usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
>  	usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
>  	usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
> -	usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT);
> +	usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT | USB_BESL_SUPPORT);
>  
>  	/*
>  	 * The Superspeed USB Capability descriptor shall be implemented by all

-- 
balbi

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